Check device features (only build non solid pipelines if feature available)

mesh/mesh.cpp

@@ -86,9 +86,9 @@ public:
 		glm::vec4 lightPos = glm::vec4(25.0f, 5.0f, 5.0f, 1.0f);
 	} uboVS;
 
-	struct {
+	struct Pipelines {
 		VkPipeline solid;
-		VkPipeline wireframe;
+		VkPipeline wireframe = VK_NULL_HANDLE;
 	} pipelines;
 
 	VkPipelineLayout pipelineLayout;
@@ -111,7 +111,9 @@ public:
 		// Clean up used Vulkan resources 
 		// Note : Inherited destructor cleans up resources stored in base class
 		vkDestroyPipeline(device, pipelines.solid, nullptr);
+		if (pipelines.wireframe != VK_NULL_HANDLE) {
 			vkDestroyPipeline(device, pipelines.wireframe, nullptr);
+		}
 
 		vkDestroyPipelineLayout(device, pipelineLayout, nullptr);
 		vkDestroyDescriptorSetLayout(device, descriptorSetLayout, nullptr);

tessellation/tessellation.cpp

@@ -69,11 +69,11 @@ public:
 		float tessAlpha = 1.0f;
 	} uboTessEval;
 
-	struct {
+	struct Pipelines {
 		VkPipeline solid;
-		VkPipeline wire;
+		VkPipeline wire = VK_NULL_HANDLE;
 		VkPipeline solidPassThrough;
-		VkPipeline wirePassThrough;
+		VkPipeline wirePassThrough = VK_NULL_HANDLE;
 	} pipelines;
 	VkPipeline *pipelineLeft = &pipelines.wirePassThrough;
 	VkPipeline *pipelineRight = &pipelines.wire;
@@ -89,11 +89,6 @@ public:
 		cameraPos = glm::vec3(-3.0f, 2.3f, 0.0f);
 		title = "Vulkan Example - Tessellation shader (PN Triangles)";
 		enableTextOverlay = true;
-		// Enable physical device features required for this example				
-		// Tell the driver that we are going to use geometry shaders
-		enabledFeatures.tessellationShader = VK_TRUE;
-		// Example also uses a wireframe pipeline, enable non-solid fill modes
-		enabledFeatures.fillModeNonSolid = VK_TRUE;
 	}
 
 	~VulkanExample()
@@ -101,9 +96,13 @@ public:
 		// Clean up used Vulkan resources 
 		// Note : Inherited destructor cleans up resources stored in base class
 		vkDestroyPipeline(device, pipelines.solid, nullptr);
+		if (pipelines.wire != VK_NULL_HANDLE) {
 			vkDestroyPipeline(device, pipelines.wire, nullptr);
+		};
 		vkDestroyPipeline(device, pipelines.solidPassThrough, nullptr);
+		if (pipelines.wirePassThrough != VK_NULL_HANDLE) {
 			vkDestroyPipeline(device, pipelines.wirePassThrough, nullptr);
+		};
 
 		vkDestroyPipelineLayout(device, pipelineLayout, nullptr);
 		vkDestroyDescriptorSetLayout(device, descriptorSetLayout, nullptr);
@@ -114,6 +113,28 @@ public:
 		textures.colorMap.destroy();
 	}
 
+	// Enable physical device features required for this example				
+	virtual void getEnabledFeatures()
+	{
+		// Example uses tessellation shaders
+		if (deviceFeatures.tessellationShader) {
+			enabledFeatures.tessellationShader = VK_TRUE;
+		}
+		else {
+			vks::tools::exitFatal("Selected GPU does not support tessellation shaders!", "Feature not supported");
+		}
+		// Fill mode non solid is required for wireframe display
+		if (deviceFeatures.fillModeNonSolid) {
+			enabledFeatures.fillModeNonSolid = VK_TRUE;
+		}
+		else {
+			// Wireframe not supported, switch to solid pipelines
+			pipelineLeft = &pipelines.solidPassThrough;
+			pipelineRight = &pipelines.solid;
+		}
+	}
+
+
 	void reBuildCommandBuffers()
 	{
 		if (!checkCommandBuffers())
@@ -413,8 +434,10 @@ public:
 		// Solid
 		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCreateInfo, nullptr, &pipelines.solid));
 		// Wireframe
+		if (deviceFeatures.fillModeNonSolid) {
 			rasterizationState.polygonMode = VK_POLYGON_MODE_LINE;
 			VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCreateInfo, nullptr, &pipelines.wire));
+		}
 
 		// Pass through pipelines
 		// Load pass through tessellation shaders (Vert and frag are reused)
@@ -425,9 +448,11 @@ public:
 		rasterizationState.polygonMode = VK_POLYGON_MODE_FILL;
 		VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCreateInfo, nullptr, &pipelines.solidPassThrough));
 		// Wireframe
+		if (deviceFeatures.fillModeNonSolid) {
 			rasterizationState.polygonMode = VK_POLYGON_MODE_LINE;
 			VK_CHECK_RESULT(vkCreateGraphicsPipelines(device, pipelineCache, 1, &pipelineCreateInfo, nullptr, &pipelines.wirePassThrough));
 		}
+	}
 
 	// Prepare and initialize uniform buffer containing shader uniforms
 	void prepareUniformBuffers()
@@ -486,12 +511,6 @@ public:
 
 	void prepare()
 	{
-		// Check if device supports tessellation shaders
-		if (!deviceFeatures.tessellationShader)
-		{
-			vks::tools::exitFatal("Selected GPU does not support tessellation shaders!", "Feature not supported");
-		}
-
 		VulkanExampleBase::prepare();
 		loadAssets();
 		setupVertexDescriptions();
@@ -532,7 +551,9 @@ public:
 			break;
 		case KEY_W:
 		case GAMEPAD_BUTTON_A:
+			if (deviceFeatures.fillModeNonSolid) {
 				togglePipelines();
+			}
 			break;
 		case KEY_S:
 		case GAMEPAD_BUTTON_X:
@@ -547,10 +568,14 @@ public:
 		ss << std::setprecision(2) << std::fixed << uboTessControl.tessLevel;
 #if defined(__ANDROID__)
 		textOverlay->addText("Tessellation level: " + ss.str() + " (Buttons L1/R1 to change)", 5.0f, 85.0f, VulkanTextOverlay::alignLeft);
+		if (deviceFeatures.fillModeNonSolid) {
 			textOverlay->addText("Press \"Button X\" to toggle splitscreen", 5.0f, 100.0f, VulkanTextOverlay::alignLeft);
+		}
 #else
 		textOverlay->addText("Tessellation level: " + ss.str() + " (NUMPAD +/- to change)", 5.0f, 85.0f, VulkanTextOverlay::alignLeft);
+		if (deviceFeatures.fillModeNonSolid) {
 			textOverlay->addText("Press \"s\" to toggle splitscreen", 5.0f, 100.0f, VulkanTextOverlay::alignLeft);
+		}
 #endif
 	}